@@ -52,6 +52,19 @@ config AK09911
help
Deprecated: AK09911 is now supported by AK8975 driver.
+config ALS31300
+ tristate "Allegro MicroSystems ALS31300 3-D Linear Hall Effect Sensor"
+ depends on I2C
+ select REGMAP_I2C
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for the Allegro MicroSystems
+ ALS31300 Hall Effect Sensor through its I2C interface.
+
+ To compile this driver as a module, choose M here: the
+ module will be called als31300.
+
config BMC150_MAGN
tristate
select IIO_BUFFER
@@ -7,6 +7,7 @@
obj-$(CONFIG_AF8133J) += af8133j.o
obj-$(CONFIG_AK8974) += ak8974.o
obj-$(CONFIG_AK8975) += ak8975.o
+obj-$(CONFIG_ALS31300) += als31300.o
obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
obj-$(CONFIG_BMC150_MAGN_I2C) += bmc150_magn_i2c.o
obj-$(CONFIG_BMC150_MAGN_SPI) += bmc150_magn_spi.o
new file mode 100644
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Allegro MicroSystems ALS31300 3-D Linear Hall Effect Sensor
+ *
+ * Copyright (c) 2024 Linaro Limited
+ */
+
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/*
+ * The Allegro MicroSystems ALS31300 has an EEPROM space to configure how
+ * the device works and how the interrupt line behaves.
+ * Only the default setup with external trigger is supported.
+ *
+ * While the bindings supports declaring an interrupt line, those
+ * events are not supported.
+ *
+ * It should be possible to adapt the driver to the current
+ * device EEPROM setup at runtime.
+ */
+
+#define ALS31300_EEPROM_CONFIG 0x02
+#define ALS31300_EEPROM_INTERRUPT 0x03
+#define ALS31300_EEPROM_CUSTOMER_1 0x0d
+#define ALS31300_EEPROM_CUSTOMER_2 0x0e
+#define ALS31300_EEPROM_CUSTOMER_3 0x0f
+#define ALS31300_VOL_MODE 0x27
+#define ALS31300_VOL_MODE_LPDCM GENMASK(6, 4)
+#define ALS31300_LPDCM_INACTIVE_0_5_MS 0
+#define ALS31300_LPDCM_INACTIVE_1_0_MS 1
+#define ALS31300_LPDCM_INACTIVE_5_0_MS 2
+#define ALS31300_LPDCM_INACTIVE_10_0_MS 3
+#define ALS31300_LPDCM_INACTIVE_50_0_MS 4
+#define ALS31300_LPDCM_INACTIVE_100_0_MS 5
+#define ALS31300_LPDCM_INACTIVE_500_0_MS 6
+#define ALS31300_LPDCM_INACTIVE_1000_0_MS 7
+#define ALS31300_VOL_MODE_SLEEP GENMASK(1, 0)
+#define ALS31300_VOL_MODE_ACTIVE_MODE 0
+#define ALS31300_VOL_MODE_SLEEP_MODE 1
+#define ALS31300_VOL_MODE_LPDCM_MODE 2
+#define ALS31300_VOL_MSB 0x28
+#define ALS31300_VOL_MSB_TEMPERATURE GENMASK(5, 0)
+#define ALS31300_VOL_MSB_INTERRUPT BIT(6)
+#define ALS31300_VOL_MSB_NEW_DATA BIT(7)
+#define ALS31300_VOL_MSB_Z_AXIS GENMASK(15, 8)
+#define ALS31300_VOL_MSB_Y_AXIS GENMASK(23, 16)
+#define ALS31300_VOL_MSB_X_AXIS GENMASK(31, 24)
+#define ALS31300_VOL_LSB 0x29
+#define ALS31300_VOL_LSB_TEMPERATURE GENMASK(5, 0)
+#define ALS31300_VOL_LSB_HALL_STATUS GENMASK(7, 7)
+#define ALS31300_VOL_LSB_Z_AXIS GENMASK(11, 8)
+#define ALS31300_VOL_LSB_Y_AXIS GENMASK(15, 12)
+#define ALS31300_VOL_LSB_X_AXIS GENMASK(19, 16)
+#define ALS31300_VOL_LSB_INTERRUPT_WRITE BIT(20)
+#define ALS31300_CUSTOMER_ACCESS 0x35
+
+#define ALS31300_DATA_X_GET(b) \
+ sign_extend32(FIELD_GET(ALS31300_VOL_MSB_X_AXIS, b[0]) << 4 | \
+ FIELD_GET(ALS31300_VOL_LSB_X_AXIS, b[1]), 11)
+#define ALS31300_DATA_Y_GET(b) \
+ sign_extend32(FIELD_GET(ALS31300_VOL_MSB_Y_AXIS, b[0]) << 4 | \
+ FIELD_GET(ALS31300_VOL_LSB_Y_AXIS, b[1]), 11)
+#define ALS31300_DATA_Z_GET(b) \
+ sign_extend32(FIELD_GET(ALS31300_VOL_MSB_Z_AXIS, b[0]) << 4 | \
+ FIELD_GET(ALS31300_VOL_LSB_Z_AXIS, b[1]), 11)
+#define ALS31300_TEMPERATURE_GET(b) \
+ (FIELD_GET(ALS31300_VOL_MSB_TEMPERATURE, b[0]) << 6 | \
+ FIELD_GET(ALS31300_VOL_LSB_TEMPERATURE, b[1]))
+
+enum als31300_channels {
+ TEMPERATURE = 0,
+ AXIS_X,
+ AXIS_Y,
+ AXIS_Z,
+};
+
+struct als31300_variant_info {
+ u8 sensitivity;
+};
+
+struct als31300_data {
+ struct device *dev;
+ /* protects power on/off the device and access HW */
+ struct mutex mutex;
+ const struct als31300_variant_info *variant_info;
+ struct regmap *map;
+};
+
+/* The whole measure is split into 2x32-bit registers, we need to read them both at once */
+static int als31300_get_measure(struct als31300_data *data,
+ u16 *t, s16 *x, s16 *y, s16 *z)
+{
+ u32 buf[2];
+ int ret, err;
+
+ guard(mutex)(&data->mutex);
+
+ ret = pm_runtime_resume_and_get(data->dev);
+ if (ret)
+ return ret;
+
+ /*
+ * Loop until data is valid, new data should have the
+ * ALS31300_VOL_MSB_NEW_DATA bit set to 1.
+ * Max update rate is 2KHz, wait up to 1ms.
+ */
+ ret = read_poll_timeout(regmap_bulk_read, err,
+ err || FIELD_GET(ALS31300_VOL_MSB_NEW_DATA, buf[0]),
+ 20, USEC_PER_MSEC, false,
+ data->map, ALS31300_VOL_MSB, buf, ARRAY_SIZE(buf));
+ /* Bail out on read_poll_timeout() error */
+ if (ret)
+ goto out;
+
+ /* Bail out on regmap_bulk_read() error */
+ if (err) {
+ dev_err(data->dev, "read data failed, error %d\n", ret);
+ ret = err;
+ goto out;
+ }
+
+ *t = ALS31300_TEMPERATURE_GET(buf);
+ *x = ALS31300_DATA_X_GET(buf);
+ *y = ALS31300_DATA_Y_GET(buf);
+ *z = ALS31300_DATA_Z_GET(buf);
+
+out:
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
+
+ return ret;
+}
+
+static int als31300_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val,
+ int *val2, long mask)
+{
+ struct als31300_data *data = iio_priv(indio_dev);
+ s16 x, y, z;
+ u16 t;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ case IIO_CHAN_INFO_RAW:
+ ret = als31300_get_measure(data, &t, &x, &y, &z);
+ if (ret)
+ return ret;
+
+ switch (chan->address) {
+ case TEMPERATURE:
+ *val = t;
+ return IIO_VAL_INT;
+ case AXIS_X:
+ *val = x;
+ return IIO_VAL_INT;
+ case AXIS_Y:
+ *val = y;
+ return IIO_VAL_INT;
+ case AXIS_Z:
+ *val = z;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_TEMP:
+ /*
+ * Fractional part of:
+ * 1000 * 302 * (value - 1708)
+ * temp = ----------------------------
+ * 4096
+ * to convert temperature in millicelcius.
+ */
+ *val = MILLI * 302;
+ *val2 = 4096;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_MAGN:
+ /*
+ * Devices are configured in factory
+ * with different sensitivities:
+ * - 500 GAUSS <-> 4 LSB/Gauss
+ * - 1000 GAUSS <-> 2 LSB/Gauss
+ * - 2000 GAUSS <-> 1 LSB/Gauss
+ * with translates by a division of the returned
+ * value to get Gauss value.
+ * The sensitivity cannot be read at runtime
+ * so the value depends on the model compatible
+ * or device id.
+ */
+ *val = 1;
+ *val2 = data->variant_info->sensitivity;
+ return IIO_VAL_FRACTIONAL;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_OFFSET:
+ switch (chan->type) {
+ case IIO_TEMP:
+ *val = -1708;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t als31300_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct als31300_data *data = iio_priv(indio_dev);
+ struct {
+ u16 temperature;
+ s16 channels[3];
+ aligned_s64 timestamp;
+ } scan;
+ s16 x, y, z;
+ int ret;
+ u16 t;
+
+ ret = als31300_get_measure(data, &t, &x, &y, &z);
+ if (ret)
+ goto trigger_out;
+
+ scan.temperature = t;
+ scan.channels[0] = x;
+ scan.channels[1] = y;
+ scan.channels[2] = z;
+ iio_push_to_buffers_with_timestamp(indio_dev, &scan,
+ pf->timestamp);
+
+trigger_out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+#define ALS31300_AXIS_CHANNEL(axis, index) \
+ { \
+ .type = IIO_MAGN, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .address = index, \
+ .scan_index = index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .endianness = IIO_CPU, \
+ }, \
+ }
+
+static const struct iio_chan_spec als31300_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .address = TEMPERATURE,
+ .scan_index = TEMPERATURE,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_CPU,
+ },
+ },
+ ALS31300_AXIS_CHANNEL(X, AXIS_X),
+ ALS31300_AXIS_CHANNEL(Y, AXIS_Y),
+ ALS31300_AXIS_CHANNEL(Z, AXIS_Z),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct iio_info als31300_info = {
+ .read_raw = als31300_read_raw,
+};
+
+static int als31300_set_operating_mode(struct als31300_data *data,
+ unsigned int val)
+{
+ int ret;
+
+ ret = regmap_update_bits(data->map, ALS31300_VOL_MODE,
+ ALS31300_VOL_MODE_SLEEP, val);
+ if (ret) {
+ dev_err(data->dev, "failed to set operating mode (%pe)\n", ERR_PTR(ret));
+ return ret;
+ }
+
+ /* The time it takes to exit sleep mode is equivalent to Power-On Delay Time */
+ if (val == ALS31300_VOL_MODE_ACTIVE_MODE)
+ fsleep(600);
+
+ return 0;
+}
+
+static void als31300_power_down(void *data)
+{
+ als31300_set_operating_mode(data, ALS31300_VOL_MODE_SLEEP_MODE);
+}
+
+static const struct iio_buffer_setup_ops als31300_setup_ops = {};
+
+static const unsigned long als31300_scan_masks[] = { GENMASK(3, 0), 0 };
+
+static bool als31300_volatile_reg(struct device *dev, unsigned int reg)
+{
+ return reg == ALS31300_VOL_MSB || reg == ALS31300_VOL_LSB;
+}
+
+static const struct regmap_config als31300_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 32,
+ .max_register = ALS31300_CUSTOMER_ACCESS,
+ .volatile_reg = als31300_volatile_reg,
+};
+
+static int als31300_probe(struct i2c_client *i2c)
+{
+ struct device *dev = &i2c->dev;
+ struct als31300_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->dev = dev;
+ i2c_set_clientdata(i2c, indio_dev);
+
+ ret = devm_mutex_init(dev, &data->mutex);
+ if (ret)
+ return ret;
+
+ data->variant_info = i2c_get_match_data(i2c);
+ if (!data->variant_info)
+ return -EINVAL;
+
+ data->map = devm_regmap_init_i2c(i2c, &als31300_regmap_config);
+ if (IS_ERR(data->map))
+ return dev_err_probe(dev, PTR_ERR(data->map),
+ "failed to allocate register map\n");
+
+ ret = devm_regulator_get_enable(dev, "vcc");
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable regulator\n");
+
+ ret = als31300_set_operating_mode(data, ALS31300_VOL_MODE_ACTIVE_MODE);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to power on device\n");
+
+ ret = devm_add_action_or_reset(dev, als31300_power_down, data);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add powerdown action\n");
+
+ indio_dev->info = &als31300_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->name = i2c->name;
+ indio_dev->channels = als31300_channels;
+ indio_dev->num_channels = ARRAY_SIZE(als31300_channels);
+ indio_dev->available_scan_masks = als31300_scan_masks;
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ als31300_trigger_handler,
+ &als31300_setup_ops);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "iio triggered buffer setup failed\n");
+
+ ret = pm_runtime_set_active(dev);
+ if (ret < 0)
+ return ret;
+
+ ret = devm_pm_runtime_enable(dev);
+ if (ret)
+ return ret;
+
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_autosuspend_delay(dev, 200);
+ pm_runtime_use_autosuspend(dev);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "device register failed\n");
+
+ return 0;
+}
+
+static int als31300_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct als31300_data *data = iio_priv(indio_dev);
+
+ return als31300_set_operating_mode(data, ALS31300_VOL_MODE_SLEEP_MODE);
+}
+
+static int als31300_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct als31300_data *data = iio_priv(indio_dev);
+
+ return als31300_set_operating_mode(data, ALS31300_VOL_MODE_ACTIVE_MODE);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(als31300_pm_ops,
+ als31300_runtime_suspend, als31300_runtime_resume,
+ NULL);
+
+static const struct als31300_variant_info al31300_variant_500 = {
+ .sensitivity = 4,
+};
+
+static const struct als31300_variant_info al31300_variant_1000 = {
+ .sensitivity = 2,
+};
+
+static const struct als31300_variant_info al31300_variant_2000 = {
+ .sensitivity = 1,
+};
+
+static const struct i2c_device_id als31300_id[] = {
+ {
+ .name = "als31300-500",
+ .driver_data = (kernel_ulong_t)&al31300_variant_500,
+ },
+ {
+ .name = "als31300-1000",
+ .driver_data = (kernel_ulong_t)&al31300_variant_1000,
+ },
+ {
+ .name = "als31300-2000",
+ .driver_data = (kernel_ulong_t)&al31300_variant_2000,
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, als31300_id);
+
+static const struct of_device_id als31300_of_match[] = {
+ {
+ .compatible = "allegromicro,als31300-500",
+ .data = &al31300_variant_500,
+ },
+ {
+ .compatible = "allegromicro,als31300-1000",
+ .data = &al31300_variant_1000,
+ },
+ {
+ .compatible = "allegromicro,als31300-2000",
+ .data = &al31300_variant_2000,
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, als31300_of_match);
+
+static struct i2c_driver als31300_driver = {
+ .driver = {
+ .name = "als31300",
+ .of_match_table = als31300_of_match,
+ .pm = pm_ptr(&als31300_pm_ops),
+ },
+ .probe = als31300_probe,
+ .id_table = als31300_id,
+};
+module_i2c_driver(als31300_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ALS31300 3-D Linear Hall Effect Driver");
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");